1. Field of the Invention
The present invention relates to a container closure which has "child-resistant" and "not child-resistant" positions.
2. Background-Description of the Prior Art
Many types of container closures that are difficult for young children to operate have been known in prior art and are generally designated as "child-resistant" closures. It is often the case, however, that the means employed to render a closure "child-resistant" makes the closure difficult to operate by adult users, especially in the case where a physical disability caused by either a physical injury to the hand or a disease process such as arthritis, as by way of example, decreases manual dexterity. Accordingly, many pharmaceutical companies provide "not child-resistant" closures for their product containers and many adults request "not child-resistant" closures for prescription medicine containers.
In response to many adults not wanting "child-resistant" closures for product containers, closures having "child-resistant" and "not child-resistant" positions have been disclosed in prior art such as the closure assembly disclosed by U.S. Pat. No. 4,346,809 to Kusz. Kusz discloses a "child-resistant" closure assembly that utilizes a resiliant liner, that, when employed in one relative angular orientational alignment renders the closure "child-resistant," but may be removed and replaced in a particular angular orientational alignment to render the closure "not child-resistant." U.S. Pat. No. 4,103,797 to Morris discloses a unitary reversible closure for sealing a container that, when applied in one direction forms a "child-resistant" closure and when reversed end for end and reapplied to the container is "not child-resistant." Many adults, however, do not return closures to a "child-resistant" position because of the difficulty involvled or subsequent difficulty in removing the closure.
Another type of "child-resistant" closure assembly that is known in the prior art employs two or more closure members assembled in a permanent nested configuration. While many such closure assemblies are operated by two simultaneous movements, such as depressing the closure assembly while turning and are therefore difficult to operate by many adults, several closure assemblies are disclosed that employ means to simplify their operation. For example, U.S. Pat. No. 4,285,437 to Morris, discloses a closure assembly comprising two nested closure members assembled in a fixed axial relationship by a rotationally free engagement whereby the closure members rotate freely relative to each other. A push button tab formed therewith the outer closure member may be depressed when the outer closure member is in a particular angular orientational alignment to provide transmission of opening rotational torque to the inner closure member for subsequent removal of the closure assembly. When the closure is reapplied to the container, tightening the closure causes the tab to automatically return to the "child-resistant" position. Once a child learns the particular angular orientational alignment necessary to depress the tab and operate the closure, however, it is as easy for the child to operate the closure as the ease required by adult users.
It is also known in the prior art to provide a "child-resistant" closure and container assembly wherein the closure assembly may be converted to a "not child-resistant" position as exemplified by U.S. Pat. No. 4,393,977 to Willingham. Willingham discloses a closure- container assembly wherein axial pressure may be applied through an opening in the outer closure member to disengage an inner closure member from the container, wherein the closure assembly may be subsequently lifted from the container. Willingham's closure container assembly anticipates using a single axial movement to move the closure assembly to a "not child-resistant" position, but the closure assembly is of use only with the disclosed container and is not adaptable for use on containers employing closure rotational engagement means, such as, by way of example, containers with a threaded-neck portion.
As far as is known, it is not known in the prior art to provide a "child-resistant closure" assembly, for use on containers employing closure rotational engagement means, that may be moved to a "not child-resistant" position when the closure is in any relative angular orientational alignment by a single axial movement, remains in the "not child-resistant" position during subsequent use, and which can be returned to a "child-resistant" position by a further application of a single axial movement.